ASP.NET API: No database provider has been configured for this DbContext

问题:

I am trying to connect to a MySql database from my .Net Core API project.

This is my context class:

public class MyContext : DbContext {     public MyContext() { }      public MyContext(DbContextOptions<MyContext> options)          : base(options) { }      public MyContext(DbContextOptions options)          : base(options) { }          ... } 

and this is my startup.cs:

public void ConfigureServices(IServiceCollection services) {     services.AddMvc();      string MyConnectionString = "server=localhost;port=3306;user=root;password=*****;database=my_db";     services.AddDbContext<MyContext>(options => options.UseMySQL(MyConnectionString)); } 

I know this question has already been asked a million times, but I still can't fix it.

Edit: In controllers, I instantiate my MyContext using the parameterless constructor.

回答1:

Let's try something else :

First, in your DbContext create OnConfiguring method :

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)     {         optionsBuilder            .UseMYSQL("... connection string ...");                } 

Secondly, on the beginning of you ConfigureServices method, configure the DbContext this way :

services.AddDbContext<MyContext>(); 

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